Avian Influenza (Bird Flu) (cont.)

Mary D. Nettleman, MD, MS, MACP

Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

John P. Cunha, DO, FACOEP

John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.

What is bird flu?

Bird flu (avian influenza) is a disease caused by an influenza virus that
primarily affects birds. In the late 1990s, a new strain of bird flu arose that
was remarkable for its ability to cause severe disease and death, especially in
domesticated birds such as ducks, chickens, or turkeys. As a result, this strain
was called highly pathogenic (meaning very severe and contagious) avian
influenza and termed H5N1. A new strain of bird flu has been identified in
China. The influenza A virus is termed H7N9 (H7N9 Chinese bird flu). The
identification of the virus was reported Mar. 31, 2013; the new strain is
different from the H5N1 bird flu virus.

Since the identification of highly pathogenic influenza, infected birds have
been found in Asia, Europe, the Middle East, and Africa. Careful control
measures, including destroying infected flocks and vaccinating healthy birds,
have reduced the number of cases, but the virus continues to exist in poultry
flocks in areas of Asia and Africa. Bird flu from the highly pathogenic strain
is not found in the United States at this time. Although the H1N1 "swine flu"
pandemic strain contained some bird flu genes, it was not the same strain as the
original H5N1 bird flu.

The virus spreads through infected birds shedding the virus in their saliva,
nasal secretions, and droppings. Healthy birds get infected when they come into
contact with contaminated secretions or feces from infected birds. Contact with
contaminated surfaces such as cages might also allow the virus to transfer from
bird to bird. Symptoms in birds range from mild drops in egg production to
failure of multiple major organs and death.

The first human case of illness from highly pathogenic avian influenza
(termed HPAI in older literature) was identified in 1997, and 622 cases have
been identified since then, with deaths worldwide numbering 371 as of March
2013. Human cases of highly pathogenic bird flu have been largely confined to
Southeast Asia and Africa. Mutations often occur in the virus, and it is
possible that some mutations could create a more contagious virus that could
cause a regional epidemic or a worldwide pandemic of bird flu among humans.
Fortunately, the mutations that have occurred to date have not made the virus
more contagious, although the concern remains. The identification of a new bird
flu strain is worrisome and only careful monitoring will give researchers more
clues about this virus strain's ability to infect humans. However, four people
in China (two in Shanghai, one in Nanjing, and one in Anhui province) have been
identified as being infected with H7N9; two have died. Health officials
worldwide are concerned.